Improvement in silvering mirrors



R. KECK.

Silverng Mirors.

Patented July 17, 1866.

, Inveomar.'

MM? M UNITED STATES PATENT OrEicE.

RUDOLF KECK, OF CHICAGO, ILLINOIS, ASSIGNOR TO F. W. WOOD, SOLON D.STANBRO, JOSIAH WARREN, AND JULIUS H. ROYCE.

IMPROVEMENT IN SILVERING MIRRORS.

Specification forming part of Letters Patent No. 56,507, dated July 17,1866.

To all whom it 'may concern;

Be it known that I, RUDOLF KEcK, of the city of Chicago, in the countyof Cook and State of Illinois, have invented a new and usefulImprovement in the lvlanufaeture of Mirrors 5 and I do hereby declarethat the following is a full and exact description th ereoi", referencebeing had to the accompanying drawings, making part of thisspecitication, in which- Figure l represents the cross-section of theframes with glass plates put in, and Fig. 2 represents the top View ofthe same.

In my specification describing` the improvement in the manufacture ofmirrors invented by me before, and for which Letters Patent bearing dateof November 7, 1865, and numbered 50,874, have been granted to myassignees, itA was alleged that a sheet of india-rubber or other badconductor ot' electricity, being put against the face ot' a glass plateimmersed in a suitable silvering-solution, would preserve it clear fromsilverin g, while the back side of the same plate, being' freely exposedto the action ot the solution, would be silvered, in consequence ofwhich allegation a convenient apparatus was by me devised.

The experience proved, however, that the use of india-rubber or othernon-conductors of electricity does not answer the purpose 5 that it doesnot preserve the side ofthe glass plate covered with it and immersedinto silveringsolution from being silvered also; and that considerableadditional labor is required for scraping the metal oit' the face of theplate before it. can be used as a mirror. This induced me to deviseanother and entirely different method ot' manufacturing` mirrors, and toenable others skilled in the art to make and use -my invention, Iwillnow describe its construction and operation.

Two light square wooden frames, A and B, are put upon each other, theirwidth being regulated by the size of mirrors to be manufactured, whiletheir length may be taken at will or in accordance with the size of theroom oi' the building. A partition, C, made out of veneering-wood, thickpasteboard, or some other light and suitable material, is put betweenthe frames, thus serving as a bottom to the upper frame and making a vatout'ot it. The frames and partition are fastened together by screws orother means.

The upper frame or vat is divided longitudinally by a low partition, D,whose both sides, as also those of the frame A, are made slantmg.

The frames, with their partitions, are painted with solution ofasphaltum or other substance that does not react on silvering-solution,making, at the same time, the frames water-tigh t.

The operation consists in the following: The upper frame or vat istilled with silvering-solution to the top of the sianting sides, andtheglass plates a a are put upon it, their edges resting on the sla-ntingsides of the frame A and the partition D, spaces of halt an inch beingleft between the plates for the purpose of conveniently placing them inor taking them out. In about twenty minutes, the sides ofthe plates thathave been lying on the solution being silvered the plates are taken out,and when dry their silvered sides receive a coat of suitable varnish,while the frames are tilted over, the old solution poured out, the freshsolution put in, and new glass plates put in and adjusted.

It will be perceived from the above description that by this method onlythe back side of the glass plate is silvered, while the faceside remainsperfectly clean; hence the additional labor of scraping oft' unnecessarysilvering is avoided. Besides this, the whole process is simple andquick, and the expenses of constructing thev apparatus are tritling.

Having thus fully described my method ot' manufacturing mirrors, what IAclaim as my invention, and desire to secure by Letters Patent, is-

The within-described method of precipitating upon glass plates nitrateof silver or other suitable substance or substances by meanssubstantially such as herein described, or any other equivalent means.

RUDOLF KECK.

Witnesses:

H. J. Cos'rER, W. C. DODGE.

